The C β -H hydrogen in the diiron vinyliminium complexes [Fe 2 {μ-η 1 :η 3 -C γ (R')=C β HC α = N(Me)(R)}(μ-CO)(CO)(Cp) 2 ][SO 3 CF 3 ] (R = Me, 1; R = Bz, 2 (Bz = CH 2 Ph); R = Xyl, 3 (Xyl =2,6-Me 2 C 6 H 3 )) is easily removed by sodium hydride; different products are consequently formed, depending on the nature of the substituents R and R'. Thus, deprotonation of [Fe 2 {μ-η 1 :η 3 -C(R')=CHC=N(Me)(R)}(μ-COXCOXCp) 2 ][SO 3 CF 3 ] (R = Me, R' = COOMe, la; R = Me, R' = Me, 1b; R = Bz, R' = COOMe, 2a) yields the tetranuclear complexes [Fe 2 {μ-η 1 :η 2 -C(R')-CCN(Me)(R)}(M-CO)(CO)(Cp) 2 ] 2 (R = Me, R' = COOMe, 4a; R = Me, R' = Me, 4b; R = Bz, R' = COOMe, 4c). Conversely, treatment with NaH of the vinyliminium complexes [Fe 2 {μ-η 1 :η 3 -C(R')=CHC=N(Me)(R)}(μ-CO)(CO)(Cp) 2 ][SO 3 CF 3 ] (R = Me, R' = SiMe 3 , 1d; R = Me, R' = Tol, 1e; R = Bz, R' = SiMe 3 , 2b; R = Bz, R' = Tol, 2c (Tol = 4-MeC 6 H 4 ); R = Xyl, R' = SiMe 3 , 3a; R = Xyl, R' = Tol, 3b; R = Xyl, R' = Ph, 3c) leads to the selective formation of the corresponding μ-aminocarbyne alkynyl complexes [Fe 2 -{μ-CN(Me)(R)}(μ-CO)(CO)(C≡CR')-(Cp) 2 ] (R = Me, R' = SiMe 3 , 5a; R = Me, R' = Tol, 5b; R = Bz, R' = SiMe 3 , 5c; R = Bz, R' = Tol, 5d; R = Xyl, R' = SiMe 3 , 5e; R = Xyl, R' = Tol, 5f; R = Xyl, R' = Ph, 5g). Compounds 5c,d react with methyl iodide to give the vinyliminium cations [Fe 2 {μ-η 1 :η 3 -C(R')=C(Me)C= N(Me)(Bz)}(μ-CO)(CO)(Cp) 2 ] + (R' = SiMe 3 , 6a; R' = Tol, 6b). Finally, the reactions of [Fe 2 {μη 1 :η 3 -C(R')=CHC=N(Me)(R)}(μ-CO)(CO)(Cp) 2 ][SO 3 CF 3 ] (R = Me, R' = Bu n , 1c; R = Xyl, R' = Me, 3d; R = Xyl, R' = COOMe, 3e; R = Xyl, R' = CMe 2 OH, 3f) with NaH afford the 1-metalla-2-aminocyclopenta-1,3-dien-5-one species [Fe(Cp)(CO){CN(Me)(R)CHC(R')C(O)}] (R = Me, R' = Bu n , 7a; R = Xyl, R' = Me, 7b; R = Xyl, R' = COOMe, 7c; R = Xyl, R' = CMe 2 OH, 7d). The molecular structures of 4a.CH 2 Cl 2 , 4b, 5e, and 7b have been determined by X-ray diffraction studies.